Process for the manufacture of cement.



N0- sgmss. PATENTED SEPT. 8, 1908.

W. E sNYDEE. PROCESS EOE THE MANUFACTURE 0E CEMENT.

APPLIGATION FILED MAR.11,1907.

3 SHEETSSHEET l.

WNWESSLS 11V VE IV TOR PATENTED SEPT. 8, 1908. 'W. E. SNYDER. 'PEooEss EOE THE MANUFACTURE OF CEMENT.

APPLICATION FILED MAR.11,1907.

3 SHEETSSHEET 2.

1 .n a d (IE 7 a H M Km i flw PATENTED SEPT. 8, 1908. E

I W. E. SNYDER PROCESS FOR THE MANUFACTURE OF CEMENT.

APPLICATION FILED MAR.11, 190i.

3 SHEETS-SHEET 3.

, penetration of, the cement mixture or charge I shall first proceed to describe the apparatus by I may avoid-(1) the entry into the co- WILLOUGHBY ELWOOD SNYDER, OF NAZARETH, PENNSYLVANIA.

PROCESS FOR. THE MANUFACTURE OF CEMENT.

Original application filed July :40, 1904., Serial No. 217,317.

Specification of Letters Patent.

Patented Sept. 8,1908.

Divided and this application filed March 11, 1907.

Serial No. 361,639.

To all whom it may concern:

Be it known that I, W1LLoUoirBrdCLwooi) SNYDER, a citizen of the United 5: cos, residing at Nazareth, in the coun tgiof Xorthampton and State of Pennsylvania, have invented certain new and useful lmprovr-unents in Processes for the h'lanuiactu're oi Cement, of which the following is a speci'lication.

My invention relates to the manufacture of hydraulic and cognate cements, and my object is to provide a process for such manufacture wherein calcination is accomplished. through the agency of electricity, and wherement mixture of coal ash or other products of combustion, (2) the direct action upon, or

y the electric are, (3) the cooling of the charge of cement mixture between heats, and (4) the retention of the carbonic acid gas liberated from the mixture during calcination.

In the accompanying drawings: Figure 1 is a View of the furnace in vertical section, omitting the feed and drait coinpelling devices, and showing the rotary hearth with the means for actuating the same, the stationary hood, the arc-electrodes, the ,electromagnets and the means for-raising and lowering the hearth relatively to the arc-electrodes. Fig. 2 is a view of the -lfurnacc in plan, showing the rotary hearth with its supporting spider, the hood, the arc-electrodes, the electro-magnets, the feed pipe, the stack or draft-compelling means, the scraper and the apron therefor. Fig. 3 is a detail view in side elevation, partly in vertical section and partly in perspective, of the hearth and hood at the point of charge and discharge, showing the feed ipe, the stack, the scraper and the a ron. ig. 4 is a detail view in cross-section, of the hearth showing the scraper and the apron. Fig. 5 is a detail View, in plan, of the means for establishing electrical connection between the electro-magnets and the 'ower shaft, as shown in Fig. 1. Fig. 6 is a detail view, in elevation, showing an alternative arrangement of the eleetro-magnets. Fig. 7 is a detailview, in elevation, of the shutter or slide at the charging end oi. the hood, showin the means for raising and lowering the s iutter.

Referring to the numerals on the drawings,

illustrated therein, with special reference to its availability or the practice of my process or method of manufacture, and, having done so, shall by the aid all'ordcd in the knowledge ol the apparatus, endeavor brielly butclcarly to trace the several slcps of my process.

ln l ig. l the spider or spolicd wheel 1 carries the annular reservoir 2 from the bottom ol which rises the vertical support 2) arrying the continuous annular hearth r with its top 5 composed ol lire-brick or other suitable heat-resisting material. The vertical sup port ll of the hearth thus divides the reservoir 2 into two continuous annular U-shaped compartments. The hood (3, composed of any suitable refractory or heat resisting material is suspended over the hearth by the straps 7 depending from the frame 8. To the inner sides of the hood are secured the plates 9 which extend dowinvard into the U-shaped comparments of the reservoir 2 above doscribod. 'lhe hood (5 and its plates 9 are continuous save at the point oi charge and discharge shown in Fig. 2 and hereinafter described, and the space included by the hood above the hearth should be such. as to produce the necessary reverbcrat )ry action of the heat of the arcs, hereinafter described,

located within the hood above the hearth against the charge thereon.

At intervals in. the hood 6 openings in the opposite sides thereof are formed, as shown in Figs. 1 and 2, for the introduction of arcsupporting electrodes or carbons, the posi-' tive iarbons being indicated by the numeral 10 and the negalivc by the numeral 11. The positive and negative carbons are arranged in sets respectively, as shown in Fig. 2, and are staggered in such wise as to lay an arc across the entire width of the hearth. Each set of positive electrodes is rovided with any suit. able well-known mec ianism (not. shown) for automatically advancing or feeding the carbons to preserve an arc of the requisite con-- stancy of energy. For this purpose the mechanism shown and described in Letters Patent No. 816,753, dated April 3, 1906, granted to me ior cement burning furnace may be employed. The hearth 4 with its spider 1 is rotated by-the vertical shaft 12 mounted. in the bearing 13 in the frame 8 and upon the shoulder on the bearing 14 of the threaded sleeve hereinafter described. The pulley wheel 16 indicates any suitable means for rotating the shaft, spider and hearth. Upon the hood 6 are located the electro-magnets 17. These communicate with the shaft 12, Fig. 1, by means of the arms 29, one end of each arm being secured. to an electro-magnet and the other end being secured to the split ring 30 surrounding the shaft 12. Electrical connection with the' shaft 12 is secured by thebrushes31 carried by the ring 30, as shown in plan in Fig. 5.. Thus, referring to' Fig. 1, the current passes from the electro-magnets 17 downward through the hood and hearth, is thence conducted through the arms of the spider or spoked wheel 1 to the shaft 12, ascends the shaft 12 to the brushes 31 and thence, through the ring 30 and arms 29 back to the electromagnets 17. The course of the current is indicated by the dotted arrows in Fig. 1. The function of the electro-magnets above described is to intensify the calcining action of the arcs generated between the carbon points hereinabove described.

The means for feeding the cement or other material upon the hearth are indicated in Fig. 2 and shown in detail in Fig. 3. It consists of the feed pipe 20 opening directly upon the hearth at the charging end of the hood, the casing 21 forming the lower end of a suitable bin or hopper containing the material to be calcined, and the notched feed cylinder22 adapted to rotate in the casing 21. By the rotation of the feed cylinder 22 by any suitable mechanism (not shown) an intermittent feed of the material is obtained from the hopper and casing 2]. into the upper end of the feed pipe 20 whence it is deposited upon the hearth at the charging end of the hood. An intermittent deposit upon the hearth of the material to be calcined is desirable for the reason that a continuous charge or deposit becoming vitrified into a more or less solid and continuous mass mighttcnd to become blocked or jammed within the hood, particularly at the exit or discharge end thereof where the vitrified or calcined product is turned oft the hearth by the scraper 23 hereinafter described.

In Fig. 2 the hood 6 is seen to be continuous save for the space between its charging and discharge ends. In this space arranged the scra ver 23, disposed. diagonally across the hearth and secured either to the ends of the hood or to the straps supporting the same, as shown in. Figs. 2 and 3. To vent any portion of the calcined PIOL not from dropping into the reservoir 2 at this oint as it is scraped or diverted from the hearth the stationary apron 24 is secured either to the ends of the hood or otherwise supported, as shown in Fig. 4, the lip of the apron extending partly beneath the hearth in' such wise that the calcined product removed from the hearth by the action otthe scraper is discharged over the apron without danger of blocking up the reservoir.

In Figs. 2 and 3 the stack 25 represents lower edge and the surface of the hearth suflicient to permit the material fed thereon by the pipe 20 to enter the hood. The'exit or discharge end of the hood is open. Thus the updraft created in the stack 25 by the blower or fan causes a current of air to be drawn in at the dischargeend of the hood and to circulate through the latter a ainst the direction of revolution of the heart 1 and,

of the material deposited thereon. Each of the annular U-shapcd compartments of the reservoir 2, Fig. l, is partially filled with any suitable iluid, such as a heavy oil and the plates 9 cxtcuding down from each side of the hood into said liquid render the hood continuously airtight save at the charging and discharge ends thereof. Thus no air is drawn in under the edges of the hood. to in tcrl'crc with the circulation above described. This arrangement of parts serves the further purpose of conserving as far as possible the heat within the hood.

In the use of my furnace as embodying my process for the *alcination of cement or other cognate materials it may become desirable or necessary to employ dill'erent degrees of heat for the trmrtmcnt ol' dill'erent substances or of the same substanm. This adjustment I secure by the means shown in Fig. 1. The lower end of the vertical shaft 12 is provided wit h,a threaded sleeve 26 setscrcwed thereto and controlled by the wheel .27 mounted upon the bearing 28. By rotating the wheel 27 theshall 12 may be lowered, an opening in the base 15 being provided for the purpose. This lowers the hearth, increasing the space between the charges thereon and the carbon points above and likewise increasing the volume of air drawn through. the hood bv the draft-compclling means. The depth of the reservoir 2 and ol the plates 5) extending down into the same may be proportioned in practice to admit ol adjustment in the mannor abovc d cscribcd withir any desired limits.

By rcl'ercncl-w to Fig. 2 it'will be observed that the sets of electrodes with their accompanying clectro-imigncts are disposed at unequal distances around the hearth and hood. 'lhc-object ol this disposition is as follows: If the material to be calcined is immediately and continuously subjcctcd to the full calcining action of the electrodes from the moment it enters the charging end of the hood it may be overburncd and the product thus may be dclcrioratml. By the arrangement shown in Fig. 2 the material entering the charging end of the hood is subjected only to the reverberaction of the carbons, as

i being well understood atory heat of the hood and hearth, which is least at the point of entrance and increases as the hearth with its charge. approaches the first set of electrodes. The distance between the iirst set. of electrodes and each succeeding set progressively diminishes, thus incr asing both the direct and reverberatory heat to which the charge is subjected in its circulation through the hood from the charging end to the discharge end.

in ti l have indicated an alternative arrangement oi parts to secure the electromagnetic reinforcement ol' the calcining action of the carbons. in this arrangement the spider i carries the annular reservoir 2 and the hearth l with its lire brick coverinc 5. Air tightness at the sides of the hood (3 is secured by an extension of the sides thereof into the reservoir. lhe disposition ol' the carbons and i1 is as hereinlwl'orc described. The clectri inagnet i7 is located, as before, above the hood and is provided with the head 32 which projects dou'mvard through the top of the hood as shown. The bent arm 33 passes from the clectro-magnet l7 outward, dowmvard and upward to a point immediately below the hearth, providing a means whereby a continuous circulation oi' the elect-ro-magnetic current may be obtained for the purpose. oi? reinforcing the hereinbefore described.

In Fig. 7 is shown a means for adjusting the shutter 26 at any desired height and thus partly closing the charging end of the. hood. To one end of the. arm 34, pivoted upon the support 35, is hooked the chain 36 attached to the. top of the shutter, and the. chain 37,

principle of my furnace together with its mode of b eration. in the 'lliSl/ place, I avoid actua penetration of a charge or mass of cement mixture to be treated by the arcs or any part of the arcs, which may prevent the manufacture of a sound cement. 1 cmploy the heat derived only by radiation, deflection or reverberation oi the arcs. The are must be located a sullicient distance above the hearth to accommodate upon the hearth a charge disposed below, but not between the electrodes that sustain the arc, it that the heat of an arc most intense and that the highest its intensity is located directly within the current ot or between the electrodes supporting the arc, where, as has been specified, it is, if not too intense, at least too much concentrated for its successful employment in the manufacture of cement. it the object of my invention in part to employ such heat, tree, as it is, from products of combustion (lei cteriougi to cement at its highest c'tlicient indegree oi l l l l l l l i l i i l l l l l i i t l l i l l one end of which is secured to the top of the l i i, l t l l 'tion of successive tensity,

but without it i i bjectionable degree or manner of com l arcs through the revcrberatiiry action of the hood above the arcs. which reverberatory action, together with the direct radiation from the arcs, is directed, dctlected. and concentrated in ellicient cnergrv against. the charge upon the hearth. in order to provide for the continuous manufacture of cement upon a hooded hearth ol' annular form, it is T1800"- sary, in view oi the fact that the innnediate product oi calcination in the manufacture of cement is a clinkerorvitritied mass to deposit cement mixture in separate charges upon the hearth, because when so deposited they clinker into detached portions or cakes which may, through the. continuous rotation of the hearth, be automatically swept therefrom one by one by the scraper. Further, an ad" vantage is derived over a continuous charging feed, in securing to the charge that perfect homogeneity of calcination which is essential to the manufacture of a sound cement. Finally, it is advantageous to the practical application of heat over an extended charge or mass to be calciped in the manufacture of cement but more especially in. the applicaheats to separate charges, not only to make provision for the application of an abundant supply of oxygen to the charge while it is undergoing calcination, but also with especial reference to the several stages which it undergoes between initial and com )lete calcination. To explain more fully, the initial application ofhcat to a charge of cement mixture besides expelling moisture liberates carbonic-acid gas'in quantity. Consequently in order to promote combustion it is not only necessary to keep a constant supply of oxygen at the point of combustion, but also to draw oil the carbonic-acid gas and other impurities or deleterious iroducts generated by the combustion. ilf, lll'liBTBfOIB, suitable draft-compelling means he provided and properly a med in the manufacture, it will serve a double purpose, both of affording a fresh supply of oxygen and oi'" removing in jurious products of combos ion. Consequently i provide, by means of the stack eonn'nunicating with the charging and of the hood, for the generation of a current of air in opposition to the direction of movement of the hearth. This provides pure, air to the final combustion and conducts the current by successive stages to the point of initial combustion, whence the dense fumes gener ated by such initial combustion are conduct ed oil through the stack, without possibility of contamination of the finished product.

My present process application is a division of my application for ccrncnhburning hirnace, filed July 20, 1.904, Serial No. 217,317 upon which Letters Patent were issued to me, dated April 3rd,1906, N 0. 816,753. The furnace therein described is adapted for the practice of my process, but I consider the furnace described in this present application as exemplifying a preferable form of apparatus for the practice of my process.

What I claim is y 1. In the manufacture of cement, the process of calcination which consists in suhjeeting material suitable therefor to a series of electrically generated: heats and in' the em ployment therewith of an air the successive heats from the final to the initial heat.

2. In the manufacture of cement, the process of calcinatioi'i which consists in exhibiting acharge upon a movable hearth to the action of successive electrically generated heats, and in generating against the charge a current of air proceeding from the final to the initial heat and moving in opposition to the direction of movement of the hearth.

i i ll l (mrrentthrough and 3. In themanufacture ofcement, ess of calcination which consists in subjectin material suitable therefor upon a movalile hearth to a series of reverberatory heats generated respectively from a series of electric arcs and in the employment therewith of a current of air proceeding from the final to the initial heat and moving in opposition to the direction of movement of the hearth.

4. In the manufacture of cement, the process of calcination which consists in intermittently feeding, the material to be calcined in separate charges upon amovable hearth subjecting said charges to the reverberatory heat of a series of electric arcs located within a current of air moving in opposition to the direction of movement of the hearth.

In testimony whereof I hereto affix my signature in presence of two witnesses.

WlhhOUGllBY ELWOOD SNYDER.

the pr0el/l itnesses: 7

WILSON E. BECK, MA'rrrIE M. Woonnme. 

